What is 'Oil Flush Treatment' apart from money-grabbing

I seem to remember on Mk3/4 Cortinas the timing chain rapidly wore through the rubber tensioners!

I think the Morris Minor camchain was 'tensioned' by two rubber rings set either side of the camshaft sprocket (so the chain sideplates ran on them).

That puts more 'rubber' running in oil (ignoring oil seals, camchain tensioners / guides etc). ;-)

Cheers, T i m

I was trying to remember 50 years back how it started in reverse, I remembered the kick start still being on the engine but yes it did have a dynastart. I never realised it may have had twin points for reverse.

Oddly the honda civic hybrid has both the ability to bump start off the flywheel coils (which I think are the only charge circuit) or use a conventional starter.

I also remember dynastarts on garden tractors.

AJH

Yes the Subaru 1.8 was similarly safe as with the turbo charger the compression was reduced, hence valves and piston didn't meet.

AJH

They certainly had the dynamo as part of the OHC drive. But a conventional starter motor. Not sure it would make sense beefing up a cam drive to handle the torque of a starter. But may have had a combined dynamo and magneto, since it was driven at cam speed.

Basic two strokes run with quite a large amount of advance. To get adequate power in the opposite direction you'd need similar timing. Obvious way in those days a second set of points.

I assume our Outlander has some such arrangement. Besides starting the engine (without the noise you normally get) it charges when you running down hill etc. There is a nifty display in the ICE showing 'Energy flow'. Out of battery, into battery from engine, into battery from wheels (well generator).

I think I remember hearing the TD5 engine uses a short 'soft' pushrod section that collapses in case of the valve to piston interface?

To have an engine design where something as trivial (cost wise) as a cam belt (or tensioner / pump / other bearing) failing ... effectively writing the engine off (when it needn't) seems a bit lax to me?

Cheers, T i m

I have an SV650 with likely the same caliper, I drilled smaller diameter through holes to allow me to use a punch to drive them out after I had the same problem.

It worked!

The last Mazda 323F before the 3 has a belt. Inspect at 60K, change at

100K. Stupid design has the cam cover extend over the belt so the "inspect" costs a large rubber cam cover seal - quite expensive. The design team have clearly never serviced a vehicle at any time in their careers.

Quite a pathetic 16 valve DOHC engine for the early 2000's as it makes the same power as a 1980's PSA SOHC 8 valve carb engine fitted to Citroen BX and less power than the 1.4L Honda that Rover used in the

214Si. Though it's very much more fuel efficient and reliable than the PSA POS.

Quite. By the time an engine has "sludge" or carbon deposits the only recourse is total strip and clean by abrasion. Carbon build up is on surfaces that dry out while the engine is warm, then the thin film of oil cooks and cokes on the surface. Flushing won't get the sludge out of the engine either.

Ok.

Cool, thanks.

I'm guessing how long it takes before (and it seems it is before rather than if) they seize is a function of the environment they find themselves in. I'm not sure it would happen at all in California. ;-)

As an aside, the brake fluid was rather a dark colour and according to one of those little electronic brake / oil moisture meters was mostly water. ;-(

OOI, did you caliper have anti-squeal shims and can you remember if the little tension springs that go across the top (well bottom) of each pad and under the pins (not the double R clip) were on the inside of the pads (the disk side) and clipped over the back (towards the outside) or on the outside of the pad and clipped over to the inside?

We put these back as we found them but not sure if they are right and the HBOL doesn't show it clearly enough?

Cheers, T i m

On Hondas the most likely stuff to find in the centrifugal filter on the end of the crank is wear particles from the wet clutch. Except for the cam bearings and gears (running on main/lay shafts when not engaged) everything was ball/roller bearing and could live in oil mist.

All modern engines have non magnetic thin wall white metal bearing shells with a tin/indium overlay. Only place that magnetic material makes contact is the cam/tappets. So a magnetic sump plug will only ever detect worn cams. Any car with spray bar top end lube can be liable to cam wear if not not properly maintained. Spray bars only block if the oil hasn't been changed often enough.

"often enough"

If an engine has issues with sludge or spray bar blockage then it indicates that servicing at mileage or time "by the book" was incorrect. The engine has been operating in and should have been serviced to the "extreme conditions" service schedule.

1: Dusty conditions. 2: Towing. 3: Short journeys / stop/start. 4: Prolonged idling (city traffic waiting though more than one cycle of traffic lights). 5: Long periods of low load such as mountain descents. (never leaving 30/40mph limits?) 6: Driving in salty conditions. 7: Driving in mud/sand.

This typically requires oil changes at 1/2 the usual time/distance interval.

Makes sense. However, for the material to be carried into the centrifugal filter, it has to have come from the oil in general?

When I stripped the first Mrs's Honda C50LA (3 speed automatic step through 50cc motorbike) to apply a factory friction clutch mod (I didn't trust the bike shop to do it) because it was like a Swiss watch in there. Very well designed and built.

Aren't you only going to see any of that in a power form ('worn material' that would get caught in the filter) or big chunks if it breaks up?

Ok?

Broken gears, broken roller / ball bearings, bits broken off gear selectors or chain tensioner bars / guides (talking bikes or cars with combined engines and gearboxes)?

Like clattery Cavilers. ;-)

What about particularly short / duty cycles?

;-)

I often wondered about 'City Cars' ... cars that only go from someone's house to the shops or station? The ones who sometimes stray out onto a dual carriageway or fast AB road and still only do 27 mph. ;-)

Understood.

Also I've noticed how some vehicles (diesels especially) 'dirty' their oil very quickly, whereas other seem to take much longer?

My old MX ETX 251 Saxon Tour was such a machine because being a 2/, the oil wasn't typically contaminated by combustion blow past and so was really only a gearbox oil.

My 'Airhead' has 5 (different) oils ... engine, gearbox, swinging arm, final drive and front forks.

On the magnetic drain plugs ... I don't think I've ever removed one that didn't have a small coating of what is obviously magnetic material (it doesn't just wash off if dipped in petrol etc). Not saying there wasn't other (non magnetic) material in suspension in the oil of course ...

Cheers, T i m

In message , "Dave Plowman (News)" writes

I reckon that I wrecked my MK2 Escort engine doing something similar - ie adding a 'highly recommended' anti-sludging additive to the engine oil. Soon afterwards, when driving happily along, the engine suddenly started sounding like a ratting can of nails. Leaving it for a minute or two before continuing usually cleared the problem for a short while (especially if I drove slowly). I suspected an oil blockage, but getting the local garage to blow out the oilways didn't cure it. I think there was possibly a flap of partially released sludge somewhere, and that it would keep getting sucked up and blocking something. Since then, I feel it's usually better to 'let sleeping dogs lie'.

IIRC (but I might be wrong), some time ago there was a test using a fleet of taxis in Prague. At the normal service intervals, some had new oil and oil filter, some had only new oil, and some had only a new filter. It was found that there was least wear and tear in the engines, and generally higher reliability, with those that only had a new filter.

The coarse filter in the sump can sometimes give you warning of inpending doom by putting the oil light on when too many flakes bolck the sump filter, you turn the engine off, the flakes fall off and away you go, for a while.

I found that the crossflow pumps were quite susceptible to sludging up internally and I saw several engines wrecked by this. Happily changing the oil pump was easy on that engine, but usually came too late, I have an idea there are still a couple of new pumps in the garage, should go on ebay, anything for early escort sells.

Back in the early nineties, I worked for West Midlands Fire service, fixing radios, turnout equipment, and computers.

They had fleet of H-plate Astramax vans with the 1.7L non-turbo diesel engine. The manufacturers oil change interval was something daft like

4500 miles IIRC (when a petrol was 9000).

As you might expect, the vehicle workshops did the servicing, rather than sending it to a dealer, and they generally did it on a time basis. This was fine for all the station vans that did very few miles- hydrant inspections, chippy runs, moving the odd bit of kit to another station etc.

Our van, however, was in use pretty much all day every day, and often at night as well, driving over the entire county, heavily laden, and mercilessly thrashed. We were based in central Birmingham, covered from NW Wolverhampton to SE Coventry, and one guy lived in Telford, so it racked up the miles at a huge rate, and thanks to the schedule, only one or two oil changes in ~60k miles IIRC. It got checked/topped up regularly, at least once a week at on-call handover.

It gradually got more rattly (bearing inn mind that as a early 90s GM diesel, it was never quiet), and felt slower. Cam follower noise. One Friday afternoon, it was my turn on call, and I took the van home. Within a few yards of home, a nasty clunk, and the engine died. Managed to coast it to my house, and it got recovered. The camshaft had seized, and broken up. It ended up with a new cylinder head, but was never the same again. Our next van got serviced a lot more....